In the communication systems, since the mobile apparatuses that are of mobility use limited power of batteries as the primary power source, IEEE 802.16e/m provides different types of power-saving mode corresponding to different traffic properties in order to reduce power consumption of the mobile apparatuses. More specifically, a mobile apparatus may have to negotiate with the base station if the mobile apparatus intends to enter the sleep mode. In addition, the base station determines whether the mobile apparatus is allowed to enter the sleep mode, the type of power-saving mode in use, and the relevant parameters. The mobile apparatus entering the sleep mode may turn off the receiver/transmitter to save power. If further adjustments are made with consideration of the above and the quality of service that are acceptable to the customers, unnecessary power consumption may be further reduced.
In the 4G communication system, the operation of sleep mode is highly related to the time duration of sleep. Based on the above, various studies and patents regarding different power-saving mechanisms have been proposed. However, the studies and patents merely focus on the applicable conditions of unicast multi-connections without proposing an effective power-saving scheduling mechanism to allow the mobile apparatuses to keep the quality of service (QoS) while maintaining the power-saving function.